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Diffstat (limited to 'kernel/dma/swiotlb.c')
-rw-r--r--kernel/dma/swiotlb.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index d8e6f1d889d5..9fd73700ddcf 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -30,6 +30,7 @@
#include <linux/gfp.h>
#include <linux/highmem.h>
#include <linux/io.h>
+#include <linux/kmsan-checks.h>
#include <linux/iommu-helper.h>
#include <linux/init.h>
#include <linux/memblock.h>
@@ -901,10 +902,19 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
local_irq_save(flags);
page = pfn_to_page(pfn);
- if (dir == DMA_TO_DEVICE)
+ if (dir == DMA_TO_DEVICE) {
+ /*
+ * Ideally, kmsan_check_highmem_page()
+ * could be used here to detect infoleaks,
+ * but callers may map uninitialized buffers
+ * that will be written by the device,
+ * causing false positives.
+ */
memcpy_from_page(vaddr, page, offset, sz);
- else
+ } else {
+ kmsan_unpoison_memory(vaddr, sz);
memcpy_to_page(page, offset, vaddr, sz);
+ }
local_irq_restore(flags);
size -= sz;
@@ -913,8 +923,15 @@ static void swiotlb_bounce(struct device *dev, phys_addr_t tlb_addr, size_t size
offset = 0;
}
} else if (dir == DMA_TO_DEVICE) {
+ /*
+ * Ideally, kmsan_check_memory() could be used here to detect
+ * infoleaks (uninitialized data being sent to device), but
+ * callers may map uninitialized buffers that will be written
+ * by the device, causing false positives.
+ */
memcpy(vaddr, phys_to_virt(orig_addr), size);
} else {
+ kmsan_unpoison_memory(vaddr, size);
memcpy(phys_to_virt(orig_addr), vaddr, size);
}
}